描述了一种简单有效的溶液处理硫属化物热电材料的制备。首先,PbTe,PbSe,和SnSe是通过克级胶体合成法制备的,该方法依赖于金属乙酸盐和二苯基二硫属化合物在十六胺溶剂中的反应。所得的纯相硫属元素化物由高度结晶和无缺陷的颗粒组成,具有不同的立方,四足-,和杆状形态。粉末状的PbTe,PbSe,和SnSe产品通过放电等离子烧结(SPS)进行致密化,提供各自硫属化物的致密颗粒。扫描电子显微镜显示,SPS衍生的颗粒表现出精细的纳米/微观结构,由关键构成颗粒的原始形态决定,而粉末X射线衍射和电子显微镜分析证实SPS衍生的颗粒是纯相材料,保持胶体合成产物的结构。所得溶液处理的PbTe,PbSe,和SnSe表现出低的导热性,这可能是由于在精细微结构上形成的增强的声子散射。对于未掺杂的n型PbTe和p型SnSe样品,达到预期的中等热电性能。相比之下,未掺杂的n型PbSe表现优异,在673K时获得了0.73的优异品质因数,大多数优化的PbSe基热电材料。总的来说,我们的发现有助于设计有效的溶液处理硫系热电体。
A simple and effective preparation of solution-processed chalcogenide thermoelectric materials is described. First, PbTe, PbSe, and SnSe were prepared by gram-scale colloidal synthesis relying on the reaction between metal acetates and diphenyl dichalcogenides in hexadecylamine solvent. The resultant phase-pure chalcogenides consist of highly crystalline and defect-free particles with distinct cubic-, tetrapod-, and rod-like morphologies. The powdered PbTe, PbSe, and SnSe products were subjected to densification by spark plasma sintering (SPS), affording dense pellets of the respective chalcogenides. Scanning electron microscopy shows that the SPS-derived pellets exhibit fine nano-/micro-structures dictated by the original morphology of the key constituting particles, while the powder X-ray diffraction and electron microscopy analyses confirm that the SPS-derived pellets are phase-pure materials, preserving the structure of the colloidal synthesis products. The resultant solution-processed PbTe, PbSe, and SnSe exhibit low thermal conductivity, which might be due to the enhanced phonon scattering developed over fine microstructures. For undoped n-type PbTe and p-type SnSe samples, an expected moderate thermoelectric performance is achieved. In contrast, an outstanding figure-of-merit of 0.73 at 673 K was achieved for undoped n-type PbSe outperforming, the majority of the optimized PbSe-based thermoelectric materials. Overall, our findings facilitate the design of efficient solution-processed chalcogenide thermoelectrics.